Tamper-proof locking assembly for underground electrical vaults



Apnl 28, 1970 l, M RCRWELLO Erm. 3,508,363 TAMPER-PROOF LOCKING ASSEMBLY FOR UNDERGROUND ELECTRICAL vAULTs 1 Filed 'Jupe 19, 1968 ff ffl-g '7' if 'FJ 7 U.S. Cl. 52-20 9 Claims ABSTRACT OF THE DISCLOSURE A tamper-proof assembly for fastening a cover to an underground electrical vault which has a top open to the surface. The assembly includes a cylindrical vault with a pair of apertures extending through opposite sides of the vault near the top edge thereof and a cover for the vault having a pair of openings near opposite edges thereof which maybe positioned near the corresponding apertures in the sides of the vault. An L-shaped pin is provided for each of the sets of openings and apertures. Each pin has a headed upper end which engages the cover through the opening in the cover and a lower end which engages one of the apertures in the vault.

BACKGROUND OF THE INVENTION The invention relates to the tamper-proof locking of electrical enclosures and, more particularly, to the tamperproof fastening of covers to the open ends of underground electrical vaults.

Theunderground installation of electricaldistribution systems is becoming increasingly widespread. In such systems electrical apparatus such as switches, connection devices and transformers are installed in underground vaults having a top accessible from the surface. Covers or grates are then fastened to the vault to close the open top. Since such electrical apparatus is commonly energized by relatively high voltages, the danger ofunauthorized entrance into such vaults is obvious. For this reason it is desirable to make entry into such vaults diicult for unauthorized persons.

It has been common practice to fasten coversto underground vaults by means of bolts passing through the covers to engage means fastened to the vaults, such as angle brackets fastened to the upper interior side wall of the vault. The heads of such bolts would be4 accessible from above the cover, and the bolts would be screwed into place by turning a tool engaging the heads. Such an assembly provides undesirably relatively easy access to the interior of the vault. In order to make entry more difficult, penta-headed bolts were used for this purpose because it is somewhat difiicult to turn such lbolts without a special tool.,This ty-pe of prior art assembly not only did not provide the high degree of security desirable in such installations, but was relatively complicated and expensive.

SUMMARY OF THE INVENTION It is, therefore, an object of the invention to provide means for fastening covers to the tops of underground electrical vaults which provide a high degree of tamper resistance.

It is another object of the invention to provide fastening means of the aforedescribed type which is economical in construction.

Other objects and advantages will become apparent to those skilled in the art upon reading the following description.

The objects of the invention are accomplished by providing a vault for enclosing electrical apparatus below ground level which has a top accessible from the surface United States Patent O 3,508,363 Patented Apr. 28, 1970 iCC of the ground, a cover for closing the top of the vault ing an L-shaped pin for engaging the cover and the vault. The pin has a head at one end for engaging the cover. The pin depends downwardly within the vault and then extends horizontally through an aperture in the side of the vault. Locking or tamper-proof fastening means may then be fastened to the lower extending end of the pin. The lower extending end of the pin and the locking or tamperproof fastening means are preferably below ground level to increase the difficulty of access to the vault.

Unlike the aforedescribed prior art device, the exposed head of the pin provides no means for unfastening the cover, and the buried locking or tamper-proof device is diicult to remove for the average casual potential intruder.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical sectional view through an underground electrical vault which incorporates the present invention;

FIG. 2 is a top View of the vault shown in FIG. l;

FIG. 3 is an enlarged fragmentary view of a portion of the assembly shown in FIG. l;

FIG. 4 is a fragmentary elevation view taken on the line 4-4 of FIG. 3; and

FIG. 5 is a sectional view taken on line 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, FIG. 1 illustrates a vault 2 buried in ground 3 to its upper edge for housing electril apparatus such as a transformer 4. Vault 2 comprises a cylinder 5 preferably constructed of bituminous impregnated fibre. The bottom of vault 2 is covered with a layer of gravel 6 to provide support for transformer 4 and to promote drainage. A cover or grate 7 covers the otherwise open top of vault 2. If desired, the assembly may incorporate a tamper shield (not shown) between the cover 7 and the transformer 4. The upper edge of vault 2 is strengthened by an attached collar 10 which is also made of bituminous impregnated fibre and which surrounds the upper edge of cylinder 5. A pair of rim sectors 11 and 12 are attached to collar 10 and extend above the upper edges .of collar 10 and the cylinder 5 to form a rim for horizontally retaining cover 7. Cover 7 rests at its periphery on the upper edges of collar 10 and cylinder 5.

vA high voltage conductor 15 enters vault 2 through an aperture 16 and leads to a high voltage connector 17 fastened to the top of transformer 4. A pair of low voltage conductors 18 are connected to transformer 4 by means of a low voltage connection assembly 19 and exit vault 2 through an aperture 20 in the opposite side of vault 2.

As shown in FIG. 2, cover or grate 7 has an arrangement of slotted apertures 21 for the admission of cooling air to transformer 4. A pair of opposing slots 22 and 23 are formed in opposite edges of cover 7. A pair of corresponding recessed areas 24 and 25 surround slots 22 and 23 on the upper face of cover 7. Aligned below slots 22 and 23 are a corresponding pair of apertures 26 and 27 which pass radially through cylinder 5 and collar 10 near the upper edge of vault 2.

A pair of L-shaped pins are provided to fasten cover 7 to the top of vault 2. Pins 30 and 31 and associated elements are identical, and the details thereof are more clearly shown in FIG. 3 which illustrates pin` 30 in assembly. The phantom representation 30 illustrates pin 30 in a position which may be assumed during the process of insertion of pin 30. Pin 30 is inserted through slotted openings 22 to a position where a head 32 formed onl pin 30 engages the upper surface of cover 7 within re# cessed area 24. The opposite end of pin 30 is inserted vthrough aperture 26 from the interior of vault 2 to .the

position shown in FIG. 3. In this position the upper leg of pin 30 extends vertically from cover 7 to the vicinity of aperture 26, and the lower leg of pin 30 extends horizontally through aperture 26. An aperture 33 is formed through the lower end of pin 30 to accommodate a fastening device which could be a simple cotter key or a more sophisticated tamper-proof locking device 35 which is illustrtated.

The illustrated locking device 35 is called an expendable equipment lock and is manufactured -by Fargo Manufacturing Company, Incorporated, Poughkeepsie, N.Y. This device comprises a metallic bale 36, a body 37 and a torque-head screw 38. Installation is easily acomplished by removing the ends of bale 36 from the body and inserting one end of bale 36 through aperture 33. The body 37 is then replaced on the ends of bale 36, and the torquehead screw 38 is tightened with a wrench or pliers until its head shears off. The pointed inner end of screw 38 forces the ends of bale 36 against the inside of body 37 to firmly secure the assembly. Removal of the equipment lock 35, when required, is accomplished by using wire-cutters or a hacksaw.

As preferably illustrated, the lower extending ends of pin 30 and locking device 35 are buried beneath the surface of earth 3. The locking device 35 is, therefore, not only difficult to remove, but its existence is concealed. This concealment of the means `for opening vault 2 provides additional security from entry by the unauthorized person.

While the apparatus heretofore described is effective to accomplish the stated objects, it is not intended that the 4. The inventionas .defined in claim 2 -wherein said aperture is substantially below ground level to thereby increase the difficulty of access to said locking means.

5. In an assembly for providing tamper-proof fastening of a cover to the top of a below-ground level vault, the combination comprising:

a vault for enclosing' apparatus below ground level yand having a top lopen to the surfac of the ground;

a cover for closing said top of said vault, said cover having at least one opening therein;

an aperture extending through the side of said vault near the top of said vault; and an integral pin for fastening said cover to said Vault comprising an upper vertically extending leg having a head at its upper end, Iand a lower leg extending at substantially right angles from the lower end of said ,v upper leg in a horizontal direction, said upper leg extending through said opening, in which position said-head engages the upper surface of said cover, and said lower leg extending horizontally through said aperture to the exterior of said vault; and

fastening. means on the extending end of said lower leg for securing said pin in said vault.

6. The invention as defined in claim 5 wherein said fastening means comprises locking means fastened to said pin outside said vault, said locking means including a torque-head screw device fastened to a bale that is inserted through an aperture in said pin.

invention be limited to the preferred embodiment since it may be modified without departing from the scope of the appended claims.

We claim:

1. In an assembly for providing tamper-proof fastening of a cover to the top of a below-ground level vault, the combination comprising:

a vault for enclosing apparatus below ground level and having a top open to the surface of the ground;

a cover for closing said top of saidk vault, said cover having at least one opening therein;

an aperture extending through the side of said vault near the top of said vault; and

an integral and generally L-shaped pin for fastening said cover to said vault comprising a head at one end of said pin for engaging said cover when said pin is placed through said opening with the major portion of said pin within said vault below said cover, and means on the other end of said pin for fastening said pin tol said vault when said other end of said pin is placed through said aperture from the interior of said vault to thereby fasten said cover to said vault.

2. The invention as defined in claim -1 wherein said means on said other end comprises locking means fastened to said pin outside said vault, said locking meansy including a torque head screw that has the head sheared off on application of torque beyond that necessary to fasten said locking` means. p

3; The invention as defined in claim 1 whe-rein said aperture is substantially below ground level to thereby increase the difficulty of access to said means on said other end of said pin,

7. The invention as defined in claim 5 wherein said aperture is substantially below ground level to thereby increase the difficulty of access to said fastening means.

8. The invention as dened in claim 6 wherein said aperture is substantially below ground level to thereby increase the difficulty of access to said locking means.

9. An assembly for securing an enclosure from unauthorized entry comprising:

an enclosure for containing tamper susceptible apparatus and having an open top;

a cover for closing said top of said enclosure, said cover having at least one opening therein;

an aperture extending through the side of said enclosure near the top of said enclosure; and

an integral and generally L-shaped pin for fastening said cover to said enclosure comprising a head at one end of said pin for engaging said cover when said pin is placed through said opening with the major portion of said pin within said enclosure below said cover, and means on the other end of said pin for securely fastening said pin to said enclosure when said other end of said pin is placed through said aperture from the interior of said enclosure to therelby fasten said cover to said enclosure.

References Cited UNITED STATES PATENTS 1,384,712 Y 7/1921 Shanley 52-20 X 1,620,983 3/1927 Nichols 292-256 1,719,224 7/1929 Haase 52-20 X 2,350,018 5/1944 Dean et al. 52-20 X ALFRED C. IPERHAM, Primary Examiner Us. ci, xa, Ult-37, 292-256 

